Technical Field
The present disclosure relates generally to the field of combustion burners and methods of use, and more specifically to burners, submerged combustion glass melters, and methods of their use, particularly for melting glass forming materials.
Background Art
A submerged combustion melter (SCM) may be employed to melt glass batch and/or waste glass materials to produce molten glass by passing oxygen, oxygen-enriched mixtures, or air along with a liquid, gaseous and/or particulate fuel (some of which may be in the glass-forming materials), directly into a molten pool of glass, usually through burners submerged in a glass melt pool. The introduction of high flow rates of products of combustion of the oxidant and fuel into the molten glass, and the expansion of the gases during submerged combustion (SC), cause rapid melting of the glass batch and much turbulence and foaming.
In the context of SCMs, known oxy-fuel burners are predominately fluid-cooled or non-fluid-cooled nozzle mix designs and avoid premixing of fuel and oxidant for safety reasons due to the increased reactivity of using oxygen as the oxidant versus air. While these designs have largely proved adequate, there remains a desire for improved fuel combustion to maximize heat release from the fuel, and possibly reduce non-waste fuel and oxygen-enriched oxidant usage, as both non-waste fuel and oxygen-enriched oxidants typically require the expenditure of funds above that when the fuel is entirely waste material and the oxidant is air.
One currently used submerged combustion burner employs a smooth exterior surface, half-toroid, water-cooled steel burner tip or nozzle in which fuel, oxidant, and ultimately a fuel/oxidant mixture ideally pass through a generally central passage of the half-toroid and then combust upon exiting. When in use, however, some of the molten and/or still solid material can enter the central passage, particularly in floor-mounted burners, coating or partially coating the interior walls of the nozzle. This may lead to restricting flow of one or more of the fuel, oxidant, and fuel/oxidant mixture, and may in extreme cases lead to partial or full plugging of the nozzle, resulting in decreased or ultimately zero heat release to the molten material and/or material being melted through that particular burner.
Development of submerged combustion burners having improved heat release and/or less susceptibility to backflow of molten material and plugging while melting glass-forming materials would be an advance in the submerged combustion art.